One of the most frequently mentioned issues with GMO foods is a vague concern about bringing genes from distantly related organisms into plants. But an international team of biologists has now found that this has occurred naturally in a major crop plant: the sweet potato. The strains of this crop that we currently cultivate had a set of genes inserted into their genomes by bacteria—the same bacteria used to create many genetically modified plants…

This plant was domesticated in South America over 8,000 years ago, and its use spread globally. While studying the RNA made in sweet potato cells, researchers found a collection of bacterial genes. Tracing them back to the DNA, they found the Agrobacterium T-DNA, along with a handful of genes from the bacteria. Further examination revealed a second cluster of genes, indicating that this natural transgenic process has happened at least twice in this lineage.